The field of the present invention generally relates to optical systems for data reading and radio frequency identification (RFID) systems for remote identification of physical objects. More particularly, the field of the present invention relates to a multiple technology data reader for reading bar code labels and RFID tags.
Optical reading systems are widely used to read data, in the form of bar codes or other encoded symbols, printed on various objects. These systems may be used for a wide variety of applications, such as inventory control and point-of-sale transactions in retail stores.
Optical reading systems may employ an optical reader that illuminates a bar code (for example) and detects light reflected from the bars and spaces of the code. In one type of optical reading system, an optical beam of light produced by a laser diode is used to scan the bar code symbol. The bars of the code absorb light, while the spaces of the code reflect light. The resulting pattern of reflected light is detected by circuitry within the optical reader. The reflected light can be detected by a photocell, photodiode, CCD array, or CMOS array sensor.
After the bar code data is received by the optical reader, the detected signal may be subject to filtering, amplification, digitization and decoding. The detected signal may be transmitted to a processor or decoder located within the optical reader, or to a separate device such as a personal computer. In systems where the signal is conveyed to a separate device, the optical reader may be connected to the external data processor by means of cables or via a wireless communication link. The wireless communication link can be implemented using radio frequency (RF) equipment or infrared (IR) transmitters and receivers, for example.
In retail stores, optical reading systems may be set up at check-out stands and may be built into a horizontal check-out counter, so that items to be purchased can be placed on a counter, deck or conveyor, and then moved through an optical reading area. Alternatively, the optical reader may be a handheld device, in the shape of a wand or gun. Typically, in operation these handheld devices are pointed or aimed at the retail item, so that a wide range of information, including price, may be read from the object.
RFID systems can be used to identify retail items by reading electronic information stored within tags or labels on the items. These systems can be used to remotely identify physical objects by the response signal sent back by the tag.
An RFID system typically employs at least two components, a xe2x80x9ctransponderxe2x80x9d or xe2x80x9ctag,xe2x80x9d which is attached to the physical item to be identified, and a xe2x80x9creader,xe2x80x9d which sends an electromagnetic signal the transponder and then detects a response. Typically, the reader emits a RF signal which is received by the transponder, after the transponder comes within an appropriate range. In response to the signal from the reader, the transponder sends a modulated RF signal sent back to the reader. The reader detects this modulated signal, and can identify the transponder by decoding the modulated signal. After identifying the transponder, the reader can either store the decoded information or transmit the decoded signal to a computer.
The transponder used in an RFID system may be either xe2x80x9cpassivexe2x80x9d or xe2x80x9cactive.xe2x80x9d A passive transponder can be a simple resonant circuit, including an inductive coil and a capacitor. Passive transponders are generally powered by the carrier signal transmitted from the reader. Active transponders, on the other hand, generally include transistors or other active circuitry, and require their own battery source.
In some retail environments, both bar code labels and RFID tags are attached to various retail items. In these environments an optical reader is needed to read the bar code label, and a separate RFID reader is needed to detect and identify the RFID tag. Without a dual-technology device embodying both bar code and RFID reading functionality, two separate devices would be needed to read both bar codes and RFID tags. Thus, there is a present need for a dual-technology bar code/RFID reader.
One example of a hand-held dual technology identification tag reading head, that can read both bar codes and RFID tags is described in U.S. Pat. No. 5,382,784, issued to Eberhardt. However, the present inventor has recognized that the system described in that patent has several drawbacks. For example, in that system, in order to operate the hand-held reader, a user must selectively actuate either the bar code reader or RFID tag reader. Moreover, at any given time, only one of readers is powered. Therefore, simultaneous operation of both the bar code reader and the RFID tag reader is not possible. In addition, when the RFID reader is selected, the output signal from the RFID reader must be converted to a format corresponding to the output signal from the bar code reader, in order to be fed into a single input port of a data receiver.
Thus, the present inventor has determined it would be advantageous to provide a dual-technology bar code/RFID reader which is capable of reading bar codes and RFID tags simultaneously, and which is more versatile than the previously described devices.
The present invention relates to a multiple technology data reader for reading optical code labels and RFID tags. In one embodiment, the multiple technology data reader includes an optical code reader sub-system and an RFID reader sub-system, each electronically connected to a device microcontroller. The device microcontroller includes a device interface for the bar code reader subsystem, and a device interface for the RFID reader subsystem. Both of these device interfaces are connected to a device communications, control and power unit. The device microcontroller is connected to a host computer via a computer bus, such as a universal serial bus (USB).
In another embodiment, the multiple technology data reader includes an optical code reader and an RFID reader, each electronically connected to a device microcontroller. The device microcontroller includes a first decoder and control means for the bar code reader, and a second decoder and control means for the RFID reader. Both of these decoder and control means are connected to a device communications, control and power unit. The device microcontroller is connected to a host computer via a computer bus, such as a USB.
In another embodiment, the multiple technology data reader includes a bar code reader and an RFID reader, each connected to a device microcontroller. The device microcontroller includes a bar code pre-processor and an RFID pre-processor, each of which are connected to a single decoding and control means. The decoding and control means is connected to a device communications, control and power unit. The device microcontroller is connected to a host computer via a USB.
Further variations, modifications and alternative embodiments are also described herein.